Aliphatic compounds, atmosphere ethers

In addition to aldehydes, ketones, and esters, other oxygen-containing compounds in the atmosphere include aliphatic alcohols, phenols, ethers, and carboxylic acids. These compounds have the general formulas given below, where R and R represent hydrocarbon moieties (groups), and Ar stands specifically for an aromatic moiety, such as the phenyl group (benzene less an H atom) ... 

The pentamer (yellow-green in solution, violet in the solid) is somewhat air and moisture sensitive. It begins to decompose 60 °C, but can be stored at room temperature indefinitely in an inert atmosphere. The compound is soluble in acetone, methanol, acetonitrile, and THF and insoluble in hydrocarbons and aliphatic ethers. It does not lose CO at an appreciable rate in solution at room temperature, but does so at elevated temperatures with the formation of larger clusters.4 The product purity is best assayed by UV-Vis spectroscopy, where traces of [Pt3(CO)6]4 appear as a shoulder near 620nm on the 706nm peak of [Pt3(CO)6]j-. IR (THF, cm-1) 2057(s), 1896(w), 1872 (m), 1845 (w), 1831 (w). UV-Vis [THF, Araax, (e,... 

The 1,2-addition of a cyanide ion to a carbonyl compound to form a cyanohydrin is a fundamental carbon-carbon bond-forming reaction in organic chemistry, and has frequently been at the forefront of advances in chemical transformations. In 2000, Belokon and North developed a catalytic system based on a vanadium-salen complex (Scheme 9.1). The synthesis of vanadium(iv) complex 1 was accomplished by refluxing a mixture of the corresponding Schiff base with vanadium(iv) sulfate and pyridine in ethanol under an argon atmosphere. A very low catalyst loading of 0.1 mol% was employed to convert aromatic and aliphatic aldehydes to cyanohydrin silyl ethers 3 with enantioselectivities of 68-95% after 24 h. Further investigations... 

The thermo-oxidative degradation mechanism of TPEEs is proposed based on results of the analysis of model compounds (dibu-tyleneglycol dibenzoate and diethyleneglycol dibenzoate), as well as of the copolymers based on PBT and PEO or PTMO in an oxygen atmosphere [99,100]. The oxidation of polyfether ester)s is initiated in the polyether soft segment at the methylene carbon atom adjacent to the ether oxygen (a-carbon atom). Thermal oxidation mainly results in the formation of a stable ester with aliphatic and aromatic acids and an alcohol, beside CO and CO2. 

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